Discharge-valve for compressors.



N0. 7|3,63l. Patented Nov. l8, I902.

F. W. GORDON.

DISCHARGE VALVE FOR COMPBESSURS.

(Application filed Mar. 17, 1902.) (No Model.)

Witnesses: Inventor I o W W I S M 5. 13M Attorney w: mums PETERS co.gNom-urm, WAsmNsYou, n. cy

ll ivirnp STATES Parnivr @nricnt FREDERICK W. GORDON, OF HARTFORD,CONNECTICUT.

DISCHARGE-VALVE FOR COMPRESSORS.

SPECIFICATION forming part of Letters Patent No. 713,631, dated November18, 1902.

Application filetLMarch 17, 1902. Serial No. 98,543. (No model.)

of a portion of the cylinder of an air-compressor fitted with myimproved dischargevalve.

In the drawing, 1 indicates the compressorcylinder, 2 its piston, 3 itspiston-rod, 4 its cylinder-head, 5 its discharge-chamber, 6 the outletfrom the discharge chamber, 7 a passage through the cylinder-headplacing the compressor-cylinder in communication with thedischarge-chamber, all of the parts thus far referred to being ofordinary construction and subject to ordinary and proper modifications;S, the discharge-valve disposed within the discharge-chamber and seatingin the passage 7 and opening toward the discharge-chamber; 9, the stemof the valve projecting outwardly through the outer wall of thedischarge-chamber; 10, a rocker fitted on the dischargechamber andhaving one end connected with valve-stem 9; 11, a tappetstem extendingthrough the discharge-chamber parallel with the axis of the compressor,its outer end being connected with rocker 10 and its inner endprojecting into the compressor-cylinder in position to be in contactwith the compressor-piston when the latter is at the end of its strokeand valve Sis closed and adapted as valve 8 opens to project stillfarther into the compressor-cylinder; 12, a valve piston supported bythe dischargechamber concentric with valve-stem 9; 13, a valve-cylinderformed upon the back of the discharge-valve and fitting valve-piston 12with proper air-tightness, and 14: a tube surrounding tappet-stem 11 toprevent leakage around the stem from the discharge-chamber.

Assume the compressor to be working and the discharge-chamber to beunder pressure and that the parts are in the position indicated in thedrawing, the discharge-valve 8 being closed and the compressor-pistonready to begin its suction-stroke to'the right. As the compressor-pistonmoves to the right, the air of suction following it through the usualinlet-valve, (not shown,) discharge-valve 8 is held closed bydischarge-pressure upon its back preponderating over suction-pressureupon its front. Under these conditions the compressor-piston completesits stroke to the right and reversing begins its compressive stroke, thepressure in the compressor-cylinder constantly rising as thecompressor-piston advances. Cylinder 13 is full of air under atmosphericpressure, due to leakage-way past stem 9, and consequently the pressurein the discharge-chamber is acting upon only that annular portion of thevalve exterior to piston 12 or on an area represented by that of thevalve minus that of piston 12. WVhen the increasing pressure in thecompressor-cylinder reaches that point at which it acting 011 the innerface of the valve will preponderate over the discharge-pressure actingon the back of the valve plus atmospheric pressure in cylinder 13,acting on the back of the valve, then the valve will suddenly fiy open,the air trapped in cylinder 13 acting as a cushion,

but soon leaking out, so that the cushioning air becomes reduced to thatof the atmosphere. The areas of the valve and piston 12 may besoproportioned that this sudden opening of the valve will take place whencompression reaches the discharge-pressure or so that it will anticpateit. The valve having suddenly opened remains full open while thecompressor is discharging into the dischargechamber, tappetstem 11having protruded into the compressor-cylinder when the valve opened.\Vhen the compressor-piston nears the end of its compressive stroke,itmakes contact with the inner end of the tappet-stem and gives thevalve a movement of closure, the valve being practically closed when thecompressor-piston shall have reached the end of its stroke and closingwith positive certainty and completeness under the influence ofdischarge-pressure upon its back when the compressor-piston begins itssuction -stroke. The leakage of air from cylinder 13 may be provided forby a little extra looseness of stem 9 in its hearing or by anyequivalent arrangement, and the general disposition of cs- ICO sentialparts is manifestly subject to numerous constructional modificationswithout departure from the invention.

I claim as my invention 1. In discharge-valves for compressors, thecombination, substantially as set forth, with a compressor-cylinder,compressor-piston, discharge chamber, and discharge valve opening to thedischarge-chamber, of a piston and cylinder disposed at the back of thedischarge-valve and arranged to detract from the area thereof subject todischarge-pressure, a tappet projecting into the compressorcylinder andadapted to be engaged by the compressor-piston as it nears the end ofits compressive stroke, and connections between said tappet and thevalve whereby the movement of the tappet under the influence of thecompressor-piston causes the practical closure of the valve.

2. In discharge-valves for compressors, the combination, substantiallyas set forth, with a compressorcylinder, compressorpiston,cylinder-head, discharge-chamber at the cylinderhead, and dischargevalve disposed Within the dischargechamber and closing toward thecompressor-cylinder, of a piston fixed within the discharge-chamber andprojecting toward the discharge-valve, a cylinder engaging said fixedpiston and connected with the valve, a valve-stem, a tappet-stemprojecting into the compressor-cylinder and adapted to be engaged by thecompressor-piston as it completes its compressive stroke, and a pivotedrocker connected with the valve-stem and tappet-stem.

FREDERICK W. GORDON.

Witnesses:

W. M. S'roRRs, CHAS. T. MINGO.

